BRAKEQUIP FITTING - FEMALE SWIVEL NUT 7/16 X 20NF - 45 DEG - CHROME

It makes a real difference. When you're threading a brake line fitting by hand, the line wants to twist with the nut, and that's how you end up with a kinked or stressed line before you've even torqued anything down. The swivel lets the nut spin independently, so the line stays put while you tighten. It also cuts down on thread galling, which is a common headache when you're working with fine threads like 7/16-20 NF.